kernfs: fix kernfs_node_from_dentry()
Currently kernfs_node_from_dentry() returns NULL for root dentry,
because root_dentry->d_op == NULL.
Due to this bug cgroupstats_build() returns -EINVAL for root cgroup.
# mount -t cgroup -o cpuacct /cgroup
# Documentation/accounting/getdelays -C /cgroup
fatal reply error, errno -22
With this fix:
# Documentation/accounting/getdelays -C /cgroup
sleeping 305, blocked 0, running 1, stopped 0, uninterruptible 1
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index e5b28b0..405279b 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -39,7 +39,7 @@
return 0;
}
-static const struct super_operations kernfs_sops = {
+const struct super_operations kernfs_sops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
.evict_inode = kernfs_evict_inode,